1. Field of the Invention
The present invention relates to a motor grader and in particular to a very low-speed travel control device thereof.
2. Background Information
A motor grader is a work vehicle used for works, such as grading road surfaces and ground surfaces and removing snow, and is provided with an engine, front and rear travel wheels, a work implement including a blade and the like, and a power transmission mechanism that includes a torque converter and a transmission. The transmission is provided with a plurality of speed stages, and switching between the speed stages is conducted by manual gear shifting or a combination of manual and automatic gear shifting.
Precise finishing work may be conducted with this type of motor grader by reducing the travel speed to a very low-speed of about 1 km/h, which is lower than a forward 1 speed. Conventionally, a double engagement clutch is used when traveling at a very low speed.
For example, very low-speed travel that is lower than the forward 1 speed is made possible by causing a reverse clutch to function as a braking clutch by causing the reverse clutch to be engaged while traveling at the forward 1 speed (see Japanese Laid-open Patent No. 2002-295528).